
DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE. Secretary 

NATIONAL PARK SERVICE 

STEPHEN T. MATHER. Director 

THE SECRET OF THE BIG TREES 

YOSEMITE, SEQUOIA AND GENERAL GRANT NATIONAL PARKS 


WASHINGTON 

GOVERNMENT PRINTING OFFICE 
1920 








THE NATIONAL PARKS AT A GLANCE. ^ y\ q 

[Number, 19; total area, 10,859 square miles.] ' si ' v (\ 4 


Natioml parks in 
order of creation. 

Location. 

Area in 
square 
miles. 

Distinctive characteristics. 

Hot Springs. 

1832 

Middle Arkansas. 


46 hot springs possessing curative properties—Many 
hotels and boarding houses—20 bathhouses under 
public control. 

Yellowstone. 

1872 

Northwestern Wyo¬ 
ming. 

3,348 

More geysers than in all rest of world together— 
Boiling springs—Mud volcanoes—Petrified for¬ 
ests—Grand Canyon of the Yellowstone, remark¬ 
able for gorgeous coloring—Large lakes—Many 
large streams and waterfalls—Vast wilderness, 
greatest wild bird and animal preserve in world— 
Exceptional trout fishing. 

Sequoia. 

Middle eastern Cali- 

252 

The Big Tree National Park—12,000 sequoia trees 
over 10 feet in diameter, some 25 to 38 feet in di¬ 
ameter—Towering mountain ranges—Startling 
precipices—Cave of considerable size. 

1890 

fornia. 

Yosemite. 

Middle eastern Cali- 

1,125 

Valley of world-famed beauty—Lofty cliffs—Ro¬ 
mantic vistas—Many waterfalls of extraordinary 
height—3 groves of big trees—High Sierra— 
Waterwheel falls—Good trout fishing. 

1890 

fornia. 

General Grant.... 
1890 

Middle eastern Cali¬ 
fornia. 

4 

Created to preserve the celebrated General Grant 
Tree, 35 feet in diameter—6 miles from Sequoia 
National Park. 

Mount Rainier... 
1899 

West central Wash¬ 
ington. 

324 

Largest accessible single peak glacier system—28 
glaciers, some of large size—48 square miles of 
glacier, 50 to 500 feet thick—Wonderful subalpine 
wild flower fields. 

Crater Lake. 

1902 

Southwestern Oregon. 

249 

Lake of extraordinary blue in crater of extinct 
volcano—Sides 1,000 feet high—Interesting lava 
formations—Fine fishing. 

Wind Cave. 

South Dakota. 

17 

Cavern having many miles of galleries and numer¬ 
ous chambers contaimng peculiar formations. 

1903 


Platt. 

Southern Oklahoma... 

n 

Alany sulphur and other springs possessing medic¬ 
inal value. 

1904 

Sullvs Hill. 

North Dakota. 

li 

Small park with woods, streams, and a lake—Is an 
important wild animal preserve. 

1904 



Mesa Verde. 

Southwestern Colo- 

77 

Most notable and best preserved prehistoric cliff 
dwellings in United States, if not in the world. 

1906 

rado. 


Glacier. 

Northwestern At on- 

1,534 

Rugged mountain region of unsurpassed Alpine 
character—250 glacier-fed lakes of romantic 
beauty—60 small glaciers—Precipices thousands 
of feet deep—Almost sensational s°enery cf 
marked individuality—Fine trout fishing. 

1910 

tana. 

Rocky Mountain. 
1915 

North middle Colo¬ 
rado. 

397* 

Heart of the Rockies—Snowy range, peaks 11,000 
to 14,250 feet altitude—Remarkable records of 
glacial period. 

Hawaii. 

Hawaii. 

118 

Three separate areas—Kilauea and Mauna Loa on 
Hawaii; Haleakala on Maui. 

1916 


Lassen Volcanic.. 
1916 

Northern California... 

124 

Only active volcano in United States proper— 
Lassen Peak, 10,465 feet—Cinder Cone 6,879 
feet—Hot Springs—Mud geysers. 

Mount McKinley. 
1917 

South central Alaska.. 

2,200 

Highest mountain in North America—Rises higher 
above surrounding country than any other moun¬ 
tain in the world. 

Grand Canvon.... 
1919 

North central Arizona. 

958 

The greatest example of erosion and the most sub¬ 
lime spectacle in the world. 

Lafayette. 

Afaine coast.. 

8 

The group of granite mountains upon Mount Desert 
Island. 

1919 


Zion. 

Southwestern Utah... 

120 

Magnificent gorge (Zion Canyon), depth from 800 
to 2,000 feet, with precipitous walls—Of great 
beauty and scenic interest. 

1919 


MAR ’20” 1923 


2 































THE SECRET OF THE BIG TREES.’ 

By Ellsworth Huntington. 

Yale University, New Haven, Conn. 


In the days of the Prophet Elijah sore famine afflicted the land 
of Palestine. No rain fell, the brooks ran dry, and dire distress pre¬ 
vailed. “ Go through the land,” said King Ahab to the Prophet 
Obadiah, unto all the fountains of water and unto all the brooks; 
peradventure we may find grass and save the horses and mules alive, 
that we lose not all the beasts.” When Obadiah went forth in search 
of forage he fell in with his chief, Elijah, and brought him to Ahab, 
who greeted him as the troubler of Israel. Then Elijah prayed for 
rain, according to the Bible story, and the famine was stayed. 

From this famine in Palestine, some 870 years before Christ, to the 
forests of the Sierra Nevadas, in the year of grace 1911, is a far cry. 
The idea of investigating an episode of ancient Asiatic history in the 
mountains of California seems at first sight quixotic. Yet for the 
purpose of facilitating such an investigation the Carnegie Institution 
of Washington furnished funds, and Yale University gave the author 
leave of absence from college duties. The men in charge of both 
institutions realize that the possibilities of any line of research bear- 
no relation whatever to its immediate practical results, or even to its 
apparent reasonableness in the minds of the unthinking. The final 
outcome of any piece of scientific work may not be apparent for gen¬ 
erations, but that does not make the first steps less important. 
Already, however, our results possess a positive value. They demon¬ 
strate anew that this world of ours, with all its manifold activities, 
is so small, and so bound part to part, that nearly 3,000 years of 
time and thrice 3,000 miles of space can not conceal its unity. 

The connecting link between the past and the present, between the 
ancient East and the modern West, is found in the big trees of Cali¬ 
fornia, the huge species known as Sequoia washingtoniana . Every¬ 
one has heard of this tree’s vast size and great age. The trunk of a 

1 This article appeared in the July, 1912, number of Harper’s Magazine, and 
is reprinted here in a revised form with the addition of photographs of some of 
the big trees in the national parks. The field work was necessarily carried on 
in areas outside the parks, as no timber is cut within the reservations.—Editor. 

3 




4 


THE SECRET OF THE BIG TREES. 


well-grown specimen has a diameter of 20 or 30 feet, which is equal 
to the width of an ordinary house. Such a tree often towers 250 or 
300 feet, or six times as high as a large elm, and within 50 feet of the 
top the trunk is still 10 or 12 feet in thickness. Three thousand fence 
posts, sufficient to support a wire fence around 8,000 or 9,000 acres, 
have been made from one of these giants, and that was only the first 
step toward using its huge carcass. Six hundred and fifty thousand 
shingles, enough to cover the roofs of 70 or 80 houses, formed the 
second item of its product. Finally there still remained hundreds 
of cords of firewood which no one could use because of the prohibitive 
expense of hauling the wood out of the mountains. The upper third 
of the trunk and all the branches lie on the ground where they fell, 
not visibly rotting, for the wood is wonderfully enduring, but simply 
waiting till some foolish camper shall light a devastating fire. 

Huge as the sequoias are, their size is scarcely so wonderful as their 
age. A tree that has lived 500 years is still in its early youth; one 
that has rounded out 1,000 summers and winters is only in full 
maturity; and old age, the three score years and ten of the sequoias, 
does not come for 17 or 18 centuries. How old the oldest trees may 
be is not yet certain, but I have counted the rings of 79 that were 
over 2,000 years of age, of 3 that were over 3,000, and of 1 that was 
3,150. In the days of the Trojan War and of the exodus of the 
Hebrews from Egypt this oldest tree was a sturdy sapling, with stiff, 
prickly foliage like that of a cedar, but far more compressed. 

It was doubtless a graceful, sharply conical tree, 20 or 30 feet 
high, with dense, horizontal branches, the lower ones of which swept 
the ground. Like the young trees of to-day, the ancient sequoia and 
the clump of trees of similar age which grew close to it must have 
been a charming adornment of the landscape. By the time of Mara¬ 
thon the trees had lost the hard, sharp lines of youth, and were 
thoroughly mature. The lower branches had disappeared, up to a 
height of 100 feet or more; the giant trunks were disclosed as bare, 
reddish columns covered with soft bark 6 inches or a foot in thick¬ 
ness; the upper branches had acquired a slightly drooping aspect; and 
the spiny foliage, far removed from the ground, had assumed a grace¬ 
ful, rounded appearance. Then for centuries, through the days of 
Rome, the Dark Ages, and all the period of the growth of European 
civilization, the ancient giants preserved the same appearance, strong 
and solid, but with a strangely attractive, approachable quality. 

After one has lived for weeks at the foot of such trees, he comes to 
feel that they are friends in a sense more intimate than is the case 
with most trees. They seem to have the mellow, kindly quality of 
old age, and its rich knowledge of the past stored carefully away 
for any who know how to use it. Often in the search for scientific 
information in remote parts of the world one comes to some primitive 


THE SECRET OF THE BIG TREES. 


5 


^ illage and inquires whether there are not some old men of long 
experience who can tell the story of the past. So it is with trees; 
like old men, they cherish the memory of hundreds of interesting 
events, and all that is needed is an interpreter. 

During* the summers of 1911 and 1912 the natural course of the 
writer’s study of the climate of the past led him to attempt to learn 



MARIPOSA GROVE, YOSEMITE NATIONAL PARK. 
Photograph by Pillsbury Picture Co. 


The Mariposa Grove is situated in the southern portion of the Yosemite National 
Park, 35 miles from Yosemite Valley. There are two other groves of big trees 
in the Yosemite National Park—the Tuolumne Grove of 20 trees 17 miles 
northwest of Yosemite Valley and the Merced Grove of 40 trees 9 miles north¬ 
west of Yosemite Valley. 

from the big trees at least a part of their story. During the 3,000 
or 4,000 years covered by recorded human history, as I have shown 
in “The Pulse of Asia,” “Palestine and its Transformation,” and 
various magazine articles, the climate of western and central Asia 















high altitude, an opposite result has apparently been produced. The 
relatively dry and warm conditions of the present have changed 
lands which once were too cold for the practice of agriculture into 
places where large numbers of people can live in comfort by means 
of that pursuit. Thus there appears to have been a change in the 
location of the regions best suited to human occupation. The change 


THE SECRET OF THE BIG TREES. 




5.** f *f 


and of the countries around the Mediterranean Sea appears to have 
changed. On the whole the climate seems to have grown drier, so 
that regions which once were fertile have now become desert. Far¬ 
ther north, however, or in regions which are cold and damp because of 


BASE OF GRIZZLY GIANT, MARIPOSA GROVE, YOSEMITE NATIONAL PARK. 
Photograph by Pillsbury Picture Co. 













THE SECRET OF THE BIG TREES 


7 



THE GRIZZLY GIANT, MARIPOSA GROVE, YOSEMITE NATIONAL PARK. 
Photograph by Pillsbury Picture Co. 

Height, 204 feet; 93 feet in circumference and 29 feet in diameter at base; 
04 feet in circumference and 20 feet in diameter at a point 10 feet above 
the ground. 



8 


THE SECRET OF THE BIG TREES. 


has not proceeded regularly, however, but in a pulsatory fashion. It 
seems to have been interrupted by centuries of exceptional aridity 
on the one hand and of exceptional moisture on the other. When 
these pulsations of climate are compared with the course of history 
a remarkable agreement is noticed. Among a mass of minor details 
this apparent relationship may be concealed, but the broad move¬ 
ments of races, the rise and fall of civilization, seem to show a de¬ 
gree of agreement with climatic changes so great that it scarcely 
seems possible to avoid the conclusion that the two are intimately 
related. Unfavorable conditions of climate, such as a change toward 
aridity in regions already none too well supplied with water, have 
apparently led to famines, epidemics, economic distress, the decline 
of trade, misgovernment, migrations, wars, and stagnation; while 
favorable changes have fostered exactly opposite conditions. 

This theory strikes so profoundly at the roots of all historical in¬ 
terpretation and is of such fundamental importance in its bearing 
on the future of nations and of the human race as a whole that it 
demands most careful testing. The first step in carrying on the 
necessary tests is obviously to determine the exact degree of accuracy 
of our conclusions as to the dates and nature of climatic changes. 
Only when that has been done are we prepared to proceed to a fuller 
investigation of the relation of the changes to historic events. 

After some years had been spent in a study of this great problem 
from various standpoints in Asia, the logical thing seemed to be to 
take up the same lines of work in some other continent and see how 
far the two agreed. Fortunately I was invited by Dr. D. T. Mac- 
Dougal to cooperate with the Department of Botanical Research of 
the Carnegie Institution of Washington in a study of the climate of 
the southwestern part of the United States. In general the phe¬ 
nomena of ancient ruins, old strands of inclosed salt lakes, the gravel 
terraces of rivers, and the distribution and agriculture of the prehis¬ 
toric population seemed to indicate that the climatic history of Amer¬ 
ica has been the same as that of Asia. The results, however, were 
unsatisfactory in two respects. In the first place, previous to the 
time of Columbus we know almost nothing about the dates of events 
in America, and hence it is impossible to know whether the apparent 
climatic fluctuations of America agree in time with those of Asia. 
In the second place, a theory is a dangerous thing. Strive as he will, 
the author is apt to be partial to it and to interpret all that he sees in 
such a way as to fit his preconceived ideas. During my work in Ari¬ 
zona, !New Mexico, and old Mexico I knew that when its results were 
announced critics would say, “ That is all very interesting, but not 
convincing. You went out West expecting to find evidences of 
pulsatory changes of climate during historic times, and, of course, 
you found them. We will wait a while before we believe you.” 


THE SECRET OF THE BIG TREES 


9 



W A WON A TREE, MARIPOSA GROVE, YOSEMITE NATIONAL PARK. 

Photograph by Pillsbury Picture Co. 

Height, 227 feet; diameter, 26 feet through the opening; 10 feet above the 
ground the diameter is 19 feet and the circumference is 60 feet. The road 
was cut through this tree in 18S0. 






10 


THE SECRET OF THE BIG TREES. 


Manifestly it was necessary to devise some new line of research 
which should not only furnish dates, but should prove positively the 
existence or nonexistence of changes of climate, and should do it in 
such a way that the investigator’s private opinions, his personal 
equation, so to speak, should not be able to affect his results. The 
necessary method , was most opportunely suggested by an article 
published in the Monthly Weather Review in 1909 by Prof. A. E. 
Douglass, of the University of Arizona. In regions having a 
strongly marked difference between summer and winter it is well 
known that trees habitually lay on a ring of wood each }^ear. The 



CROSS SECTION OF A SEQUOIA SHOWING THE GROWTH RINGS. 

wood that grows in the earlier part of the season is formed rapidly 
and is soft in texture, while that which grows later is formed slowly 
and is correspondingly hard. Hence each annual ring consists of a 
layer of soft, pulpy wood surrounded by a thinner layer of harder 
wood which is generally of a darker color. Except under rare con¬ 
ditions only one ring is formed each year, and where there are two 
rings by reason of a double period of growth, due to a drought in 
May or June followed by wet weather, it is usually easy to detect 
the fact. In the drier parts of the temperate zone, especially in 
regions like Arizona and California, by far the most important factor 
in determining the amount of growth is the rainfall. Prof. Douglass 
measured some 20 trees averaging about 300 years old. He found 
that their rate of growth during the period since records of rainfall 











THE SECRET OF THE BIG TREES. 11 

have been kept varies in harmony with the amount of precipitation. 
Other investigators have since done similar work elsewhere, and it 
is now established that in regions with cold winters and dry summers 
the thickness of the annual layers of growth gives an approximate 
measure of the amount of rain and snow. 


Obviously the best trees upon which to test the theory of climatic 
changes are the big trees of California. They grow at an altitude 
of 6,000 or 7,000 feet on the western slope of the Sierra Nevadas. 
Abundant snow falls in winter and there is a fair amount of rain 
up to about the 1st of June, but the rest of the warm season until 
the end of September is dry. Hence the conditions are highly 


MARIPOSA GROVE, YOSEM1TE NATIONAL PARK. 
Tbotograph by I’illsbury Picture Co. 






12 


THE SECRET OF THE BIG TREES. 


favorable to the formation of distinct, easily-measured rings. The 
size- of the trees makes the rings fairly thick, and hence easy to 
see. The only difficulty is that the number of trees which have been 
cut is small. The region where they grow is relatively inaccessible, 
the huge trunks are very difficult to handle, and the wood is so soft 
that its uses are limited to a few purposes for which great durability 
is required. Hence several years may pass without the cutting of 
more than a few scattering trees. The resistance of the wood to 
decay is so extraordinary, however, that stumps 30 years old are 
almost as fresh as when cut, and their rings can easily be counted. 
As climatic records they are as useful as trees that were cut the 
present year, if only one can ascertain the date when they were felled. 

Toward the end of May, 1911, I left the train at Sanger, near 
Fresno, in the great inner valley of California, and with two assist¬ 
ants drove up into the mountains through the General Grant National 
Park to a tract belonging to the Hume-Bennett Lumber Co. There 
we camped for two weeks, and then went to a similar region, some 
60 miles farther south on the Tulare River, east of Portersville. Few 
parts of the world are more delightful than the Sierras in the early 
summer. In the course of our work we often tramped through val¬ 
leys filled with the straight, graceful cones of young sequoias over¬ 
topped by the great columns of their sires. Little brooks or rushing 
streams full of waterfalls flowed in every depression, and a drink 
could be had whenever one wished. On the sides of the valleys, 
where the soil is thin and dry, no young sequoias could be seen, al¬ 
though there were frequent old ones, a fact which suggests that 
conditions are now drier than in the past. Other trees, less exacting 
in their demands for water, abound in both their young and old 
stages, and one climbs upward through an array of feathery pines, 
broad-leaved cedars with red bark, and gentle firs so slender that 
they seem like veritable needles when compared with the stout 
sequoias. 

We tramped each day to our chosen stumps, sometimes following 
old chutes made by the lumbermen to guide the logs down to the 
valleys, and sometimes struggling through the bushes, or wandering 
among uncut portions of the primeval forests. Often there was 
frost on the ground during the first week or two, and the. last rains 
of the spring made the ground oozy, while the flat tops of the stumps 
smoked in the summer sun as soon as the clouds disappeared. Our 
method of work was simple. As soon as we reached a place where 
sequoias had been cut, we began prospecting for large stumps. The 
method of cutting the trees facilitated our work by furnishing a 
smooth sawed surface. Before the lumbermen attack one of the 
giants they build a platform about it 6 feet or more above the ground 
and high enough to be clear of the flaring base of the trunk. On this 


THE SECRET OF THE BIG TREES. 


13 



two men stand and chop out huge chips, sometimes a foot and a half 
long. As the cutting proceeds a great notch is formed, flat on the 
bottom and high enough so that the men actually stand within it. 
In this Avav they chop 10 feet more or less into the tree, until they 


approach the center. Then they take a band saw 7 15 or 20 feet long 
and go around to the other side. For the next few 7 days they pull 
i the great saw back and forth, soaking it liberally in grease to make 
it slip easily, and driving wedges in behind it in order to prevent 
the w 7 eight of the tree from resting on the saw 7 . Finally, when the 
tree is almost cut through, more wedging is done, and the helpless 
trunk topples over with a thud and a stupendous cracking of branches 


MARIPOSA GROVE, YOSEMITE NATIONAL PARK. 
* Photograph by Pillsbury Picture Co. 





14 


THE SECRET OF THE BIG TREES. 


that can be heard a mile. The sawn surface exposes the rings of 
growth so that all one has to do is to measure them, provided the 
cutting has taken place recently. In the case of older stumps we 
sometimes were obliged to scrape the surface to get rid of the pitchy 
sap which had accumulated on it. In other cases, especially where 
the stumps had been burned, we had to chisel grooves or take a whisk- 
broom and sweep off an accumulation of needles and dirt. ' 

When all was ready, two of us lay down on our stomachs on the top 
of the stump, or it might be on two stumps standing close together, 
while the third sought the shade, or the sun, or a shelter from the 
rain, as the weather might dictate. The two who were on the stump 
were equipped with penknife, ruler, and hand lens. The ruler was 
placed on the flat surface of the stump with its zero at the edge of 
the outer ring. Then we counted off the rings in groups of 10, read 
the ruler and called off the number to the one who sat under shelter 
with notebook and pencil. Had the lumbermen seen us we should 
have appeared like crazy creatures as we la}^ by the hour in the sun 
and rain calling out “ forty-two,” and being answered by the recorder, 
“ forty-two ”; “ sixty-four,” “ sixty-four ”; “ seventy-eight,” “ seven¬ 
ty-eight,” and so on, interminably. It was not inspiring work merely 
to measure, and it was distinctly uncomfortable to lie on one’s stom¬ 
ach for hours after a hearty meal. Often it was hard to see the 
rings without a lens, and in some cases even the lens scarcely showed 
them all, for the smallest were only two-hundredths of an inch thick, 
very different from some of the big ones, half an inch thick. Never¬ 
theless, the work was decidedly interesting. If we were busy on 
different radii of the same tree there was always a rivalry as to who 
would finish first, but undue haste was tempered by the danger that 
the results of our two measurements might not agree. The chief 
interest therefore lay in seeing how nearly the same number of rings 
would be counted on different radii. If we were at work on dif¬ 
ferent trees the rivalry was as to whose tree would turn out oldest; 
for, like the rest of mankind, we had a feeling of personal merit if 
the thing with which we by pure chance were concerned happened to 
turn out better than that of our neighbor. 

One of our chief difficulties lay in the fact that in bad seasons one 
side of a tree often fails to lay on any wood, especially in cases where 
a clump of trees grow together in the sequoias’ usual habit, and the 
inner portions do not have a fair chance. Often we found a dif¬ 
ference of 20 or 30 years in radii at right angles to one another; and 
in one extreme case, one side of a tree 3,000 years old was 500 years 
older than the other, according to our count. All these things neces¬ 
sitated constant care in order that our results might be correct. 
Another trial lay in the fact that in spite of the extraordinary dura¬ 
bility of the wood, a certain number of decayed places are found, 


THE SECRET OF THE BIG TREES. 


15 


especially at the centers of the older trees, exactly the places which 
one most desires to see preserved. Even these decayed places, how¬ 
ever, added their own small quota of interest. Looking down into 



measuring the annual rings. 

the damp, decayed holes, we frequently saw the heads of greenish 
frogs, which slowly retreated if we became inquisitive and poked 
them. At other times, in drier places, lizards of a smooth, un- 












1G 


THE SECRET OF THE BIG TREES. 


pleasant complexion of brownish gray wriggled hastily into cavities 
in the rotten wood. Once I pulled off a large decayed slab from the 
side of a stump, and started back in surprise when two creatures 



GENERAL GRANT TREE. GENERAL GRANT NATIONAL PARK. 

Height, 2G4 feet; diameter, 35 feet. The General Grant Grove, in the park 
of the same name, has an area of 235 acres and contains 190 trees exceeding 
10 feet in diameter. 

with yellowish-brown bodies and black wings flew out. I was about 
to look for a bird’s nest when one of my companions called out 
“ Bats.” 





















THE SECRET OF THE BIG TREES. 17 

The frogs, lizards, and bats did not trouble us, and, fortunatety, we 
were free from mosquitoes. There was one creature, however, which 
sometimes seriously interfered with our work. As we lay on our 
stomachs, our left fists resting on the black surface of a stump to prop 


our unshaven chins, and our right hands rapidly touching ring after 
ring with a penknife as we counted our decades—as we lay thus, with 
eyes closely focused at a distance of about 8 inches, frightful forms 
came rushing into the field of vision. They were black and horny, 
with powerful nippers on their heads, and with white hairs on their 


NEAR CAMP SIERRA, SEQUOIA NATIONAL PARK. 







18 


THE SECRET OF THE BIG TREES. 


abdomens, giving them a moldy look. They seemed nearly as large 
as mice, and their speed of movement was positively alarming. With 
open nippers they rushed at our rulers and knives and tried them to 
see if they were edible. Sometimes they even nippd our hands, and 
more than once one of us uttered a sharp exclamation and jumped so 
as to throw knife and ruler to the winds and cause the waste of 10 
or 15 minutes in finding the place again. When we brushed the crea¬ 
tures away and looked at them from the normal distance they proved 
to be nothing but large black ants, about half an inch long. More 
pertinacious insects I never saw. Again and again I brushed an ant 
away to a distance of 6 or 8 feet, and watched that same ant turn the 
moment it alighted and rush back to the attack, and it did this not 
once but five or six times. 

During the 12 weeks that we were in the mountains in the two 
seasons of 1911 and 1912 we succeeded in measuring over 450 trees* 
79 of which were 2,000 or more years of age. The others were of 
various ages down to 250 years, for we measured a considerable num¬ 
ber of relatively young trees for purposes of comparison. The proc¬ 
ess of constructing the climatic curve from the data thus obtained is 
less simple than might at first appear. The obvious method is to 
ascertain the average growth of all the trees for each decade, from 
the earliest times to the present, and then to draw a curve showing 
how the rate has varied. The high places on such a curve will indi¬ 
cate times of comparative moisture, while the low places will indicate 
aridity. This method is too simple, however, for it takes no account 
of the fact that all trees grow faster in youth than in old age. Each 
species has its own characteristic curve of growth, as it is called. 
For example, during the first 10 years of its life the average Sequoia, 
washingtoniana grows about an inch in radius, that is, it reaches a 
diameter of 2 inches; at the age of 200 years the average tree adds 
about nine-tenths of an inch to its radius each decade; at the age of 
500 years about six-tenths of an inch; and at the age of 1,700 only 
three-tenths. These figures have nothing to clo with the rainfall, but 
indicate how fast the tree might be expected to grow if they were 
subject at all times to the average climatic conditions, without any 
variations from year to year. 

Evidently, if we desire to institute a fair comparison between the 
growth of a tree 200 years old and of one 1,700 years old, we must 
either multiply or divide by 3. By applying such corrections to 
each measurement among the 105,000 which made up the work of our 
two summers, we are able to eliminate the effect of differences in the 
ages of the trees. The process is purely mathematical and depends in 
no respect upon the individual ideas of the computer. In addition to 
the correction for age, there is another, which I have called the cor¬ 
rection for longevity. What sort of tree is likely to have a long life* 


THE SECRET OF THE BIG TREES. 


19 


Is it a vigorous, well-grown tree, the kind that one would pick out as 
especially flourishing in its youth? Not at all. The tree which is 
likely to live to a ripe old age of two or three thousand years grows 



SEQUOIAS ON GIANT FOREST ROAD, SEQUOIA NATIONAL PARK. 

The Giant Forest has an area of 3.200 acres and contains 500,000 trees, of 
which 5,000 exceed 10 feet in diameter. There are 11 other groves in tie 
Sequoia National Park ranging from 10 to 2,000 acres m area and containing 
from G to 3,000 trees exceeding 10 feet in diameter. 


slowly in its early days, 
or two-thirds as great as 


Its actual rate of growth may be only half 
that of the trees which attain an age of 500 







1100 1000 900 800 700 GOO 500 400 300 200 100 BC AD 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 


20 


THE SECRET OF THE BIG TREES. 



or 1,000 years. Hence, in order to 
institute a fair comparison between 
the rate of growth in the days of 
Darius and now it is necessary to 
make still further corrections. This 
process, like the other, is purely 
mathematical. The only difficulty is 
that in order to secure high accuracy 
a large number of trees of all ages 
is necessary. It is easy to obtain 
plenty of young trees under 2,000 
years of age, but older ones are so 
scarce that we have not obtained 
enough to render the corrections 
fully exact. Hence in the earlier 
parts of the curve, the details are 
less exact than could be desired, and 
the fluctuations are relatively too 
great, since they are not smoothed 
out by the use of a large number of 
trees. In the portion of the curve 
since about 100 B. C., however, the 
fluctuations for minor periods and 
also for centuries show no appre¬ 
ciable errors except such as are due 
to special accidents. Nevertheless 
there is some doubt as to whether 
the curve as a whole in its descent 
from early times down to the pres¬ 
ent should slope more or less than is 
here shown. 

The accompanying diagram sums 
up the results of our work on the 
big trees as compared with the re¬ 
sults of work of an entirely differ¬ 
ent kind upon the climatic fluctua¬ 
tions of Asia. Horizontal distance 
indicates time; the diagram begins 
at the left-hand end with 1300 B. C., 
and ends on the right with 1900 
A. D. Vertical distance indicates a 
greater or less amount of rainfall 
or more or less favorable condi¬ 
tions of plant growth. The solid 
line is the curve of the sequoias. 
During the periods where it is high, 















































THE SECRET OF THE BIG TREES. 


21 


abundant moisture stimulated rapid growth; where it is low. periods 
of aridity lasting often for centuries checked the growth of the trees. 
The other curve, the dotted line, is reproduced unchanged from the au- 



GENERAL SHERMAN, GIANT FOREST, SEQUOIA NATIONAL PARK. 

Height, 2S6 feet; diameter, 36 feet. 


thor’s volume on “Palestine and its Transformation. It represents 
the state of our knowledge of the changes of climate of western an 
central Asia at the time when that volume was written in 1910. I he 











22 


THE SECRET OF THE BIG TREES. 


evidence upon which it is based is of very diverse types, and varies 
greatly in accuracy and abundance at different periods. For example, 
the low portion of the curve about 1200 B. C. is based on records of 
ancient famines, and upon the fact that at that time great movements 
of desert peoples took place in such a way as to suggest that the des* 
erts had become much less habitable than formerly. A few hundred 
years later the curve is high, because at this time not only did great 
prosperity prevail in regions which are now poverty stricken for lack 
of rainfall, but the kings of Assyria and the other countries lying 
near the Arabian Desert appear to have been able to take their 
armies in comparative comfort across regions where small caravans 
can not now pass, and which even the hardy Arab raiders avoid. 
At a later time, 300 A. D., the curve drops low, because at this period 
a great number of towns were abandoned in central Asia and in all 
the drier parts of the Continent; trade routes which had formerly 
been much frequented were absolutely given up in favor of those 
where water and forage were more easily obtained; and in coun¬ 
tries like Syria stagnation seems to have prevailed, as is indi¬ 
cated by the scarcity of building operations during these years. 
The curve dips low at this point simply because evidences of 'aridity 
began to be conspicuous; but probably it dips too low, for there is 
as yet no means of obtaining exact data. In the seventh century 
A. D. evidence of the same kind as in the third causes the curve to 
drop still lower, but here we have additional proof of aridity in 
the form of traditions of prolonged famines in Arabia. Moreover, 
at about this same time the waters of the Caspian Sea and of other 
lakes without outlets were not replenished by rain, and hence fell 
to a level so low that buildings were built upon what is now the 
bottom of the lake. Then, at a later date, about 1000 A. D., the ruins 
in the desert were partially reoccupied, the old trade routes began 
to revive, the lakes rose higher than their present level, and prosperity 
was the rule in many regions which had formerly suffered from 
aridity. These bits of evidence, gathered here and there, have en¬ 
abled the curves to be drawn, but accuracy is as yet out of the question. 
At most the curves are a mere approximation, showing some of the 
main climatic pulsations, but likely to be greatly modified as further 
investigation is made. On the whole there are indications that 
further knovdedge of the Asiatic curve will prove that it is much 
more like the California curve than now T appears. Yet in the main 
the tw T o curves even now 7 show 7 a considerable degree of agreement, 
and in that agreement lies the strongest evidence that both are cor¬ 
rect in principle, although they may be wrong in detail. 

Let us begin at the left-hand end far back at the time of the Trojan 
War. There, about 1200 B. C., both curves drop very 1ow t , indicat¬ 
ing an epoch of sudden and severe desiccation. That particular 


THE SECRET OF THE BIG TREES. 


23 


period, historians tell us, was one of the most chaotic in all history. 
The warlike progenitors of the Greeks swarmed into the country 
where they were later to grow great, the Mittani or Hittites came 
down out of the mountains into northern Mesopotamia, tribes from 
Arabia and the Libyan Desert swarmed into Egypt and brought 
-civilization down to the lowest possible ebb, famines such as that 
in the days of Joseph appear in the Egyptian chronicles, the lands 
surrounding Arabia on the north and northwest were swamped by 
the great Aramean invasion, and, in general, war, migrations, and 
disaster prevailed. If America was then inhabited we can scarcely 
doubt that similar disasters took place there; for, if the trees are to 
be trusted, vast areas in dry regions such as Mexico and the south¬ 
western part of the United States, the only places where dense agri¬ 
cultural populations could have dwelt, must have fallen olf tremen¬ 
dously in productivity. 

Some fluctuations of the California curve, such as the upward bend 
between 1000 and 1100 B. C., are missing in that for Asia, not neces¬ 
sarily because they did not exist, but more probably because no facts 
yet happen to have been lighted upon which furnish evidence of 
them. The famine in the days of Elijah appears in both curves. Ap¬ 
parently at that time the climate did not become extremely dry, noth¬ 
ing like so bad as it had been a few hundred years earlier during the 
twelfth century, but there was a rather distinct falling off in the 
amount of rainfall as compared with the uncommonly good condi¬ 
tions of the preceding century. About seven hundred years before 
Christ both curves stand high in the day when the Greeks were laying 
the foundations of their future greatness and the empires of Meso¬ 
potamia were at their height. Then comes a pronounced falling off, 
with a recovery three or four hundred years before Christ, another 
decline culminating about 200 B. C., and a recovery reaching a high 
point about 50 B. C. The time of Christ, the great era of universal 
peace under the sway of Rome, was apparently an epoch of favorable 
climate, a time of abundant rain and consequent good crops in all 
the countries around the Mediterranean Sea and eastward in Asia, 
as well as in California. Next comes a long period of decline cul¬ 
minating six or seven centuries after fhe time of Christ. The sudden 
drop of the Asiatic curve about 300 A. D. is probably exaggerated, 
as are those from 550 to 650 A. D. and in 1200. Nevertheless, there 
can be little question as to the general agreement of the two curves 
in showing that an epoch of extraordinary aridity reached its climax 
in the seventh or eighth century of our era, and that another period 
of aridity occurred in the thirteenth century. Previous to the sev¬ 
enth century the Roman world had been in the direst straits because 
of the invasions of barbarians, driven from their homes, it would 
seem, by increasing aridity and the consequent difficulty of obtaining 


24 


THE SECRET OF THE BIG TREES. 


a living. Then, toward the end of the long period of drought, there 
occurred the tremendous outpouring of the Arabs, unified by Moham¬ 
medanism, as is universally agreed, and also spurred by hunger, as 
we infer from a study of climate. Thus the Dark Ages reached their 
climax. No period in all history, save that which centers 1200 B. C., 
was more chaotic; and that early period also appears to have been a 
time of greatly diminished rainfall. 

It is impossible here to trace further the correspondence of the two 
curves and their relation to history. The essential point is this: By 
means of a rigid mathematical test we have worked out the climatic 
changes of California. From ruins, lacustrine strands, traditions, 
famines, and many other lines of evidence we have worked out the 
changes in Asia. Thus by methods absolutely dissimilar we have 
constructed curves showing climatic fluctuations in parts of the world 
10.000 miles apart. In essentials the two agree in spite of differences 
in detail. It therefore seems probable not only that climatic pulsa¬ 
tions have taken place on a large scale during historic times, but that 
on the whole the more important changes have occurred at the same 
time all around the world, at least in the portion of the north tem¬ 
perate zone lying from 30° to 40? north of the Equator. This, in 
itself, does not prove that great historic changes have occurred in 
response to climatic pulsations, but it goes far in that direction. 
It introduces a new factor into that most profound and far-reaching 
of the problems of history—the cause of the rise and fall of nations* 

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